Power transmission mechanism



A 18, 1953 T. HINDMARCH 2,648,990

POWER TRANSMISSION MECHANISM Filed March 30, 1951 2 Sheets-Sheet 1 Q Q- E a Aug. 18, 1953 T. HINDMARCH 2,648,990

POWER TRANSMISSION MECHANISM Filed March 30, 1951 2 Sheets-Sheet 2 i 3 Q r )1 Q .NQ "Q Fw Q l 1L I E *b/ s w u N Q? a alien/T122 rfizzclmcbr c 'be considered.

Patented Aug. 18, 1953 umreo "fsTArE-s, PATENT o-FFICZE* Application M's-a so, 1951, Serial No. 218,39 In Great Britain June 18, 1947 This invention relatesto. power transmission mechanisms in which it is required to transmit power from two or more input shafts to one or more output shafts with ahead and astern or reverse directions of running and also a neutral position. v

Such transmissions usually embody one or more idler wheels forthe reverse running but the object of the present invention is to provide a power transmission of the kind inquestion without the necessity for providing any idler wheels so that the transmission will be particularly suitable for use in cases where light weight and space restrictionsare important factors to The. invention consists in a power transmission mechanism comprising two or more units each having a first shaft, a second shaft mounted for rotation parallel thereto, a clutch mounted on said first shaft and having an inner member which is drivingly connected to the said-first shaft, a clutch mounted on said second shaft and having an inner member which is drivingly connected to said second shaft-the clutch on the first shaft having an outer member drivingly engaging an outer member of the clutch on the second shaft by means of teeth on each said member, means for driving oneof the members of the clutch on the said first shaft, an output shaft having a gear wheel thereon which is driven alternatively in opposite directions by the engagement and disengagement of the appropriate clutches, the pair of shafts of at least one unit being common with the pair of shafts of at least one other unit, and means to engage and disengage the clutches collectively as required.

The neutral position in the transmission will be given when both clutches are disengaged.

Further features of the invention will be apparent from the description given hereafter.

The accompanying drawings illustrate several modes of carrying out the invention.

Figure 1 is a view of a form of drive for two prime movers.

Figure 2 shows a slight modification of Figure 1.

Figure 3 is a view, partly in section, of a drive for four prime movers, and

Figure 4 is a similar view to Figure 3 showing a slight variation.

Figure 1 shows a form of drive adapted for two prime movers of which the respective input shafts are shown at a and a. Each input shaft carries two pressure fluid ope-rated clutches h. 7L3, the outer driven members of the clutches h meshing with the gear wheel i on the output 3 claims. (01. 74461) shaft while the outer driven members of the clutches h? are not in mesh with the said gear wheel but mesh with the outer driven members of the clutches h'-.-The,arrangement is such that the output shaft y will be driven. in one direction of rotation when the clutches h are engaged, and in the'reverse direction when the clutches h are engaged thus driving any mechanism connected tothe output shaft g in either direction required. I

Figure 2. shows a very .similar form of drive to that shown in Figure 1, but while in Figure 1 it is essential that theprime movers run basically in opposite directions of rotation, sothat when they are arranged face to face as shown the shaftsqa,-af rotate in the same direction, the arrangement shown in Figure 2 permits the use of identicalprime movers.- For the. ahead rotation of output shaft g (Figure 2) clutch h" on shaft aand clutch h on-shaft a areengaged whereas for vtheqastern rotation clutch h? on shaft a and clutch h onshaft a are-en- :output shaft g, the: input shafts .of the prime movers being indicated at a a a and a Referring to the lower part of the figure: thetinput shaft a carries a pressure fluid operated clutch is the outer driving member of which meshes with the outer driving member of a similar clutch Z. The inner members of the clutch k are carried on a shaft m having a gear 11. engaging a ear wheel 0 on the output shaft 9. Similarly the inner members of the clutch l are carried on a shaft m having a gear wheel n which also meshes with the gear wheel 0 on the output shaft. By engaging the clutch k the output shaft is driven in one direction by the gear wheel n while the reverse direction of drive is obtained from the gear wheel n by engaging the clutch Z. Further clutches R, Z operate similarly in respect of the input shaft a3, the inner members of these clutches k, 1' being carried by the shafts m, m respectively.

In Figure 3 the input shafts of each pair of prime movers are eccentric to one another but all the input shafts run in the same direction of rotation. This arrangement therefore necessitates that the prime movers run basically in opposite directions of rotation. In Figure 4, which shows a modified arrangement of my invention, each pair of input shafts are concentric, and each two prime movers also run basically in opposite directions.

The operation of the transmission of Figure 4 will be clear when the drawing is considered. Referring to the lower part of the figure the input shaft a carries a pressure fluid operated clutch is the outer driving member of which meshes with the outer driving member of a similar clutch l. The inner members of the clutch is are carried on a shaft m having a gear n engaging a, gear wheel on the output shaft g. Similarlyf the inner membersiof the clutch Z are carried on a shaft 111/ having a gear wheel 1!. which also meshes with the gear wheel 0 on the output shaft. By engaging the clutch' k the output shaft is driven intone rdii 'e'ctiommy the gear wheel n while the reverse direction of drive is obtained from the gear whel by engaging the clutch Z. Further clutches---k',-' l' operate similarly in respect of theiinpu-t shaft a the inner members of these clutches 7a,, Z being carried by the shaft m, m respectively.

It will be understood that the principles em- 'bridied' 'in this inverition may be appliedito any number "of prime "movers d'rivirig any number (if output shaf ts, =axid the invention thereforeiis riot "to belimited to thforegoing 'details-of oonstruc- 'tionwhich are given purely -by way of exarriple =to describe-the natureo'f the inventlon and not to lirziit itsscope. For i'fwve assumethati 'Fi'giii-"e "1 and Figure 2 show aplanwiew of suh' a' transmissionwith part "of thei top housing removed,

then it is quite possible to fit'in this' topmousing a further outpu-t shaftt'gWith a gear -=wheel i -which= in turn meshes with wheels h. In such "a *case the 'tr-ansmission will have two output "Shafts.

Alternatively, f or certa'in appli'cations it :may

be desirous to have more' than two outpdt= s'haf-ts =-arran'ged such a way that 'two shaft's niesh with both 'gear wheels h whereas add-itioiial -output sha*fts' may only #mesh with either o'f "the gear wheels -h but met with both. 111 a similar"way the n-urrlber 6f input-shafts *vari'e'cl by arrariging their-respective position relw tive to wheel 2' accordingly.

Moreover while I havereferred herinto' pressure fluid-operated clu-tche's :ias bei n'g t'he most *convenient in practice, -'clutt;hes 'of other "form may be adopted "if Jde'sired.

In :any i modification of the invention it' is' fm- 4i portant to provide control mechanism for the clutches such that the correct clutches are operated simultaneously. What is claimed is: 5 1. A power transmission mechanism comprisin at least one pair of units, each unit having a first shaft, a second shaft mounted for rotationrparallel thereto, a. friction clutch mounted omsaidifirsfishft ari d having an 'i-Ifner friction 10 member drivingly connected to said first shaft, (a friction clutch mounted on said second shaft and having an inner friction member drivingly teonnetted torsaiu second shaft, the clutch on the first shafthaving an outer friction member drivingl'yengaging an outer friction member on the cliitchomthe second shaft by means of teeth on ea'ch said friction member, the pair of shafts ofoneunit in a pair of units being in extension of'the pair of shafts of the other unit in the same pair of units, each unit being driven by "wa' or'one" of*them'enibefsof the 'clutchb'n the said fiist shaft, "aiid"a'n output shaft h'avifig a "geafwheel therecsmwhi'ches driven alternatively fromea'chshaft'in'"eachunitin'oppo'site infe tidns by the engagement and disengagement 6f the appropriate clutches.

2. A ower"transmissionmeirarlism'as "claimed "in' claim' 1, 'in" which "tlrieraare at lasttifld'piiiis of iii'nltsfalfd" thes'aid' output shaftaifdthe gear wheel on said output shaft being "common "to all pairs 'of units.

'3. "A'powertransmission mecliariism as termed in-"claim 1, in which "at last'ione o'ftlie""clutcli's "in each unit is of the pressure fluid operated type.

THOMAS References oited in tire fire 6r this patent V IUN'ITEDSTATES 'PA'TEM "s 

